Hair transplants have become a common cosmetic procedure, particularly for the treatment of male pattern baldness. In a hair transplant procedure, a piece of the patient's skin having healthy growing hair is removed from a donor region on the scalp and implanted into a hairless, recipient region. Within a few months time, the transplanted hair will begin to grow and survive in a healthy manner.
In earlier hair transplant procedures, a circular cutting punch (trephine) was used to remove a round piece of skin (graft or plug) from the hair bearing donor area. A slightly smaller trephine was used to cut out a circular incision in the recipient area. The graft was then placed into the incision. Approximately 100 grafts were typically transplanted per session, with roughly four sessions being necessary to provide adequate coverage of the bald region in a male patient.
The trend over the last few years has been to utilize a larger number of much smaller grafts. This approach, while more time consuming, has various cosmetic benefits. These smaller grafts typically contain three to six hairs. The grafts can be harvested using a much smaller trephine, on the order of 1.0 to 2.5 mm in diameter. In recipient areas near the hairline, where cosmetic blending is desired, even smaller grafts, having only one to two hairs are used. The incision in the recipient area is made with a #16 gauge hypodermic needle.
Another recent variation to the transplant procedure includes the use of a scalpel blade to form slit incisions in the recipient area. Slit grafting is desirable because the incision can be made between existing hairs.
All of the above described approaches have drawbacks. First, all of the incisions cause scalp bleeding which slows surgery and leads to post surgery crusting and patient discomfort. In addition, for best results, the size and shape of the incision must be accurately controlled, requiring great surgical skill. This desire for accurate incisions is made more complicated since the instruments tend to become dull rather quickly.
A further set of problems are encountered with slit grafting since recipient tissue is not removed as it is when a trephine is used. In order to accommodate the graft, the slit must be longer than the graft. In addition, the graft tends to be compressed into the slit which creates a cosmetically unacceptable appearance.
Accordingly, it would be desirable to develop a new approach to hair transplant surgery which addresses the disadvantages of the prior techniques.